In a gas type fire extinguisher using fire extinguishing gas such as carbon dioxide, nitrogen, or fluorine compound, when the gas type fire extinguisher is put in action at the time of extinguishing a fire, the fire extinguishing gas is released so that the fire extinguishing gas concentration in the fire extinguishing area may reach an extinction concentration in about 1 minute (about 10 seconds in the case of fire extinguishing as of fluorine compound).
At this time, the fire extinguishing gas is released from an injection head installed on a ceiling or a wall for releasing the fire extinguishing gas into a fire extinguishing area, and conventionally, the injection head for gas type fire extinguisher has, as shown in FIG. 9 (a), an orifice 2 provided at an outlet of an injection head 10A connected to a piping 4 in which a fire extinguishing gas is supplied, and the fire extinguishing gas is released from the orifice 2 directly into the fire extinguishing area, or as shown in FIG. 9 (b), an orifice 2 and a conical deflector (deflection member) 5 are provided at an outlet of an injection head 10B connected to a piping 4 in which a fire extinguishing gas is supplied, and the fire extinguishing gas released from the orifice 2 is deflected by the deflector (deflection member) 5, and is released into the fire extinguishing area, or as shown in FIG. 9 (c), an orifice (not shown) and a conical tubular horn (diffusion member) 6 are provided at an outlet of an injection head 10C, and the fire extinguishing gas released from the orifice is diffused by the horn (diffusion member) 6, and is released into the fire extinguishing area.
In this manner, the conventional injection heads 10A, 10B, 10C for gas type fire extinguisher were designed to release a same volume of fire extinguishing gas from each one of a plurality of injection heads usually installed in the fire extinguishing area, and the flow rate of the fire extinguishing gas released from the injection heads is limited by the orifice 2, and because of this mechanism, when the fire extinguishing gas is released from the injection heads, it is known that noise of high level (specifically 120 dB or higher) is generated.